Green onyx is a semi precious gemstone which is mainly used for cleansing of the body. In astrology, it is a substitute of emerald (Panna) and birthstone for July month. Green onyx works as a shield on wearers and promotes good health, financial condition and strength. Black onyx is associated with root chakra and green onyx is associated with heart chakra. Onyx is available in many colours and shades like black, blue, and green and red. Onyx is a powerful gemstone which has a lot of benefits as it can cure various diseases, boost stamina, increase self control and strength of the wearer. It looks similar to emeralds.